1. Field of Invention
The present invention relates in general to valve timing control devices of internal combustion engines, and more particularly, to the valve timing control devices of a type that controls the operation timing of intake or exhaust valves of the engine in accordance with operation condition of the engine.
2. Description of Related Art
Hitherto, various types of valve timing control devices of internal combustion engine have been proposed and put into practical use particularly in the field of wheeled motor vehicles. Some of them are disclosed in Laid Open Japanese Patent Application (Tokkai) 2001-41013 and Japanese Patent Application 2001-24079. However, due to their inherent construction, the devices of such publications have failed to exhibit a satisfied performance in certain fields, That is, some are poor in saving energy, some are poor in durability and some are poor in suppressing noises.
It is therefore an object of the present invention to provide a valve timing control device of internal combustion engine, which is free of the above-mentioned drawbacks.
According to a first aspect of the present invention, there is a valve timing control device of an internal combustion engine, which comprises a drive rotation member adapted to be rotated by an output shaft of the engine; a driven rotation member coaxial with the drive rotation member, the driven rotation member rotating with a cam shaft of the engine to actuate engine operation valves; a relative angle controlling mechanism that controls a relative angle between the drive and driven rotation members; and an actuating device that actuates the relative angle controlling mechanism, the actuating device having a planetary gear unit which comprises a sun gear, a ring gear, a carrier plate and planetary gears rotatably held by the carrier plate and meshed with both the sun gear and the ring gear, the sun gear, the ring gear and the carrier plate serving as one of input, output and free elements, the input element being connectable to and driven by a rotation system that extends from the output shaft of the engine to the cam shaft of the engine, the output element being connectable to a rotation actuation element of the relative angle controlling mechanism in a manner to be controlled in rotation speed upon receiving an input force from the output shaft of the engine; and a first stopper device arranged between the output element and the drive rotation member, the first stopper device stopping a relative rotation therebetween when the relative rotation angle therebetween comes to a first predetermined degree.
According to a second aspect of the present invention, there is provided a valve timing control device of an internal combustion engine, which comprises a drive rotation member adapted to be rotated by an output shaft of the engine; a driven rotation member coaxial with the drive rotation member, the driven rotation member rotating with a cam shaft of the engine to actuate engine operation valves; a relative angle controlling mechanism that controls a relative angle between the drive and driven rotation members; and an actuating device that actuates the relative angle controlling mechanism, the actuating device having a planetary gear unit which comprises a sun gear, a ring gear, a carrier plate and planetary gears rotatably held by the carrier plate and meshed with both the sun gear and the ring gear, the sun gear, the ring gear and the carrier plate serving as one of input, output and free elements, the input element being connectable to and driven by a rotation system that extends from the output shaft of the engine to the cam shaft of the engine, the output element being connectable to a rotation actuation element of the relative angle controlling mechanism in a manner to be controlled in rotation speed upon receiving an input force from the output shaft of the engine; a first stopper device arranged between the output element and the drive rotation member, the first stopper device stopping a relative rotation therebetween when the relative rotation angle therebetween comes to a first predetermined degree, and a second stopper device arranged between the free element and the input element, the second stopper device stopping a relative rotation therebetween when the relative rotation angle therebetween comes to a second predetermined degree.
According to a third aspect of the present invention, there is provided a valve timing control device of an internal combustion engine, which comprises a drive rotation member adapted to be rotated by an output shaft of the engine; a driven rotation member coaxial with the drive rotation member, the driven rotation member rotating with a cam shaft of the engine to actuate engine operation valves; radially extending guide grooves formed in one surface of the drive rotation member; a circular guide plate arranged to rotate relative to the drive and driven rotation members, the circular guide plate being formed with a spiral guide groove at one surface thereof that faces the radially extending guide grooves; guided members each being slidably guided by both the spiral guide groove and one of the radially extending guide grooves; link arms each having one end pivotally connected to the driven rotation member and the other end to which corresponding one of the guided members is connected; an actuating device that actuates the circular guide plate to rotate relative to the drive and driven rotation members; a stopper device that restricts a rotation of the circular guide plate relative to the drive and driven rotation members, wherein when, upon operation of the actuating device, the circular guide plate is rotated relative to the drive and driven operation members, each of the guide members is forced to slide in both the spiral guide groove and the corresponding one of the radially extending guide grooves to induce a relative rotation between the drive and driven rotation members; and wherein the stopper device comprises a first member that is provided by the circular guide plate and a second member that is provided by the drive rotation member, the first and second members contacting with each other to stop the relative rotation between the circular guide plate and said drive rotation member when a relative rotation angle therebetween comes to a predetermined degree.
Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings.